{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T02:06:13Z","timestamp":1792721173176,"version":"4.5.0"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"18","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1995,8,29]]},"abstract":"<jats:p>An EPR \"spectroscopic ruler\" was developed using a series of alpha-helical polypeptides, each modified with two nitroxide spin labels. The EPR line broadening due to electron-electron dipolar interactions in the frozen state was determined using the Fourier deconvolution method. These dipolar spectra were then used to estimate the distances between the two nitroxides separated by 8-25 A. Results agreed well with a simple alpha-helical model. The standard deviation from the model system was 0.9 A in the range of 8-25 A. This technique is applicable to complex systems such as membrane receptors and channels, which are difficult to access with high-resolution NMR or x-ray crystallography, and is expected to be particularly useful for systems for which optical methods are hampered by the presence of light-interfering membranes or chromophores.<\/jats:p>","DOI":"10.1073\/pnas.92.18.8239","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T09:17:21Z","timestamp":1149067041000},"page":"8239-8243","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":340,"title":["Determination of the distance between two spin labels attached to a macromolecule."],"prefix":"10.1073","volume":"92","author":[{"given":"M D","family":"Rabenstein","sequence":"first","affiliation":[{"name":"Department of Chemistry, Lawrence Berkeley Laboratory, University of California, Berkeley 94720, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Y K","family":"Shin","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Lawrence Berkeley Laboratory, University of California, Berkeley 94720, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1995,8,29]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.92.18.8239","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T13:50:13Z","timestamp":1649857813000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.92.18.8239"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,8,29]]},"references-count":0,"journal-issue":{"issue":"18","published-print":{"date-parts":[[1995,8,29]]}},"alternative-id":["10.1073\/pnas.92.18.8239"],"URL":"https:\/\/doi.org\/10.1073\/pnas.92.18.8239","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1995,8,29]]},"assertion":[{"value":"1995-08-29","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}